Native budworm caterpillar activity and moth trapping
Caterpillar activity reports
- Northern agricultural region (Yuna, Chapman Valley, East Geraldton down to Mingenew)
- Binnu
- Coorow
- Pithara
- Beacon
- Mullewa
- Mingenew
- Carnamah
- Moora
Growers and consultants are encouraged to be aware of high numbers of native budworm caterpillars now being found in some areas. With many crops in the vulnerable pod ripening growth stage, it is important to regularly monitor grub numbers with a sweep net to determine whether control measures are required.
Grant Thompson (Crop Circle Consulting/Landmark) reports that high numbers of native budworm caterpillars are being found in late flowering and podding canola and pulse crops in the northern agricultural region including Yuna, Chapman Valley, east of Geraldton and down through to Mingenew. Numbers ranged from 6-50 budworms per 10 sweeps of an insect sweep net and he noted that there are multiple instars present including medium size (10-20mm long) as well as very small 2-3mm caterpillars, indicating multiple moth flights and egg laying events. Grant recommended that it is important to let the sweep net contents settle for a while when inspecting so that the caterpillars start moving a bit because the tiny caterpillars can be missed amongst flower petals and numbers would be underestimated. Many pulse and canola crops in the northern agricultural region are likely to be sprayed for budworm if they have not already.
A farmer near Binnu who has been finding below threshold budworm caterpillar numbers in a lupin crop for many weeks now, has found damaging numbers of budworm caterpillars in a nearby serradella paddock, the numbers found were so high that it was necessary to spray the crop immediately.
A farmer near Coorow has reported finding between 20-100 budworm caterpillars per 10 sweeps in a podding canola crop.
An agronomist and budworm trapper near Pithara has noticed a significant increase in budworm caterpillar numbers in crops throughout the region this week after finding few if any in the preceding weeks. One of the canola crops sampled had eight caterpillars per 10 sweeps.
Ty Henning (Tekag) reports finding up to 66 budworm caterpillars per 10 sweeps in a canola crop north of Beacon, most of the caterpillars caught were less than 10mm in length.
Tim Scanlon (DPIRD) has found the following average numbers of budworm caterpillars in canola crops in 10 sweeps this week: Yuna (5), Mullewa (40), Mingenew (18), Carnamah (111) and Moora (2). No budworm caterpillars were detected in pulse or canola crops at Northam, Pingelly, York, Wickepin or Corrigin.
Native budworm moth surveillance
- Usual automated and manual trapping locations
The larger native budworm moth flights recorded by budworm trappers this week include Binnu (450 moths), Grass Patch West (338), Kirwan (234), Grass Patch NW (200), Maya (177), Cuballing (167), Kojonup (159) and Doodlakine (93).
Results of this week's automated and manual trappings are available at the department’s Native budworm moth numbers 2018.
A mapped view of the native budworm trap captures is available at cesar’s MothTrapVisWA page. Viewers need to select the desired trapping date range.
For more information on Native budworm including pesticide withholding periods refer to 2018 PestFax Issue 22 article Native budworm moth flights are increasing in numbers and distribution.
The economic spray threshold levels will vary with crop type, grain price and control cost. These thresholds can be calculated for each grower's particular situation using a simple formula outlined at the department’s native budworm threshold table.
Pesticide options for the control of native budworm can be found in the department’s Winter/Spring Insecticide Spray Chart 2018.
For more information contact Alan Lord, Technical Officer, South Perth on +61 (0)8 9368 3758 or +61 (0)409 689 468.